129729631 has 4 divisors (see below), whose sum is σ = 129753064. Its totient is φ = 129706200.

The previous prime is 129729629. The next prime is 129729641. The reversal of 129729631 is 136927921.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 129729631 - 2¹ = 129729629 is a prime.

It is a super-2 number, since 2×129729631² = 33659554318792322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129729641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1741 + ... + 16201.

It is an arithmetic number, because the mean of its divisors is an integer number (32438266).

Almost surely, 2^129729631 is an apocalyptic number.

129729631 is a deficient number, since it is larger than the sum of its proper divisors (23433).

129729631 is an equidigital number, since it uses as much as digits as its factorization.

129729631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23432.

The product of its digits is 40824, while the sum is 40.

The square root of 129729631 is about 11389.8916149365. The cubic root of 129729631 is about 506.2282698390.

The spelling of 129729631 in words is "one hundred twenty-nine million, seven hundred twenty-nine thousand, six hundred thirty-one".